PPC–Pay Per Click is an advertising program in which ads are placed on your blog and you are paid whenever your visitors click on the ads.Money is maximized as traffic increases.Sites:Google Adsense,Chitika Bidvertiser,Adbrite

CPM-Cost Per Thousand is an impression based advertising system.Advertisers place ads on your blog and you are paid based on how many times the ad shows up.All you need is pageviews and big traffic.Sites:Value Click,Tribal Fusion

In-Text Ads–They are links with double-lines below them.In-text ads should be used with caution because they annoy most readers into leaving the blog.Sites:Kontera,Vibrant Media

Text Link Ads–As the blog builds traffic.your posts become great place for links.people will pay you to put their link on your blog.it may be detrimental to your blog in Google’s algorithm.study it out before using it.Sites:Text-Link-Ads,Text-Link-Brokers

Feed Ads–An easy way to increase the advertisement on your blog is by adding them to your rss feeds.set up Feedburner for your blog and monetize it with Google Adsense.Sites:Feedburner,BidVertiser,Pheedo

Pop-up Ads–These annoying ads may be great for some of your niche blogs or sub-domains.Not worth putting on blogs you want to build a community on.Sites:Adbrite,Tribal Fusion,PayPopup,PopupAd,Adversal